A3.1

Question 1

What is the function of the genome of a living organism?

Answer 1

-To store information that directs the development and function of cells.
-To regulate the expression of genes.
-To act as a blueprint for the organism’s physical characteristics.

Question 2

One possible reason that breeding between members of different species produces hybrids is due to a mismatch in the number of _____________.

Answer 2

chromosomes

Question 3

Which term is used for the exchange of genetic material between individuals within the same or different species?

Answer 3

same species - genetic recombination
diff. species -horizontal gene transfer

Question 4

The sex of an individual can be determined by analysing their karyotype.

Answer 4

true

Question 5

Speciation

Answer 5

One pre-existing species splits into two or more species.

Question 6

List the characteristics by which chromosomes are paired and arranged on the karyogram.

Answer 6

Using size, banding patterns and centromere location.

Question 7

There are many ways to create a dichotomous key

Answer 7

true

Question 8

define organism

Answer 8

-a biological system functions as an original life form
-composed of cells

Question 9

define variation

Answer 9

differences between members of a group
-can be discrete or continuous

Question 10

List sources of genetic variation within a species.

Answer 10

-mutations (changes in the sequences of genes in DNA)
-gene flow (moment of gene from diff. populations of organisms)
-sexual reproduction (random fertilization of egg & sperm)
-meiosis (random assortment of gametes)

Question 11

discrete variation

Answer 11

-usually influenced by only one or a few genes
-snapdragon petal color (red, white, pink)
-blood type (A, B, AB, O)

Question 12

continuous variation

Answer 12

-traits that vary on a quantitative level (can be measured)
-result of interaction btwn many diff. genes (environment also plays a part)
-height
-body mass

Question 13

another name for variation within a species

Answer 13

intraspecies variation

Question 14

Compare variation within and between species. ​

Answer 14

within species - some individual have traits suited to survive (reproduce & pass on genes)
between species - (depends on how closely related they are) in same species (least variation; in diff. domains (most variation)

Question 15

Define species according to the morphological species concept.

Answer 15

group of species that share common morphology (physical characteristics) distinct from other species.

Question 16

Define binomial nomenclature.

Answer 16

“two name” “system of naming”

Question 17

State four rules of binomial nomenclature formatting.

Answer 17

-genus name (starts w/ Capital letter)
-species name (lowercase letter)
-in print, the name is in italics (underline if handwritten)
-after a use in text genus name can be abbreviated (H. sapiens)

Question 18

Outline why the binomial naming system is used in science rather than local names.

Answer 18

scientists can talk the same language
-prevent confusion

Question 19

Define species according to the biological species concept.

Answer 19

group of interbreeding populations which are reproductively isolated from other such groups

Question 20

Describe limitations of the biological species concept, with mention of hybrids and geographical separation. ​

Answer 20

hybrid is the offspring resulting from sexual reproduction of two closely related but separate species
horse+donkey=mule
-bio. species concept says mule is not species since it can’t reproduce w/ other mules
-inapplicability to asexual organisms
-difficulty observing reproductive isolation in geographically separated populations
-interbreeding (hybridization) can and does occur in nature

Question 21

Explain the difficulties in distinguishing between populations and species during speciation. ​

Answer 21

genetically diverging populations may be hard to distinguish as unique species as the speciation process is occuring

Question 22

________ _______ is a distinguishing characteristic of a species.

Answer 22

chromosome number

Question 23

Explain why the typical number of chromosomes in a diploid cell is an even number.

Answer 23

because it contains two complete sets of chromosomes—one set inherited from each parent

Question 24

State the number of chromosomes in humans and in chimpanzees. ​

Answer 24

human - 46
chimpanzees - 48

Question 25

Evaluate the evidence for the hypothesis that chromosome 2 in humans arose from the fusion of chromosomes 12 and 13 with a shared primate ancestor.

Answer 25

-The combined length of chromosomes 12 and 13 in chimpanzees match the length of human chromosome 2 -banding of the arms on human chromosome 2 match 12&13 on chimps -The centromere location of human chromosome 2 matches that of chimpanzee chromosome 12 -Human chromosome 2 contains telomeric DNA in position where fusion of chromosomes 12 and 13 would have occurred

Question 26

Define karyotype

Answer 26

the observable set of chromosomes within a cell, defined by their number, size, shape, and banding patterns.

Question 27

Define karyogram

Answer 27

karyogram is the visual representation of this complete set of chromosomes, arranged in homologous pairs (ordered by size)

Question 28

Define autosome.

Answer 28

Autosomal genes are inherited by both males and females with an equal probability. -don't determine sex of organism -code for traits like height, eye color,etc.

Question 29

Define sex chromosome.

Answer 29

-The pair of chromosomes that determine the biological sex of an organism

Question 30

Deduce the sex of a human individual given a karyogram.

Answer 30

examine the 23rd and final pair of chromosomes, known as the sex chromosomes. (if a both are same length - XX female) (if one is shorter that other - XY male)

Question 31

Define genome, gene and allele.

Answer 31

genome- organism's entire set of genetic information, stored as DNA (or RNA in some viruses) in strands called nucleotides gene- specific sequence of DNA carrying instruction for particular trait/function. allele- A specific variant or alternative form of a gene (can result in variations in observable traits, known as phenotypes)

Question 32

Outline the cause and effect of “single-nucleotide polymorphisms” in genomes.

Answer 32

cause- single nucleotide substitution, deletion, or insertion in the genome when cell copies its DNA effect- Some SNPs no effect, while others alter gene function/expression, cause a phenotypic change

Question 33

Describe reasons why a larger genome does not necessarily indicate presence of more genes.

Answer 33

-some of the genes may be non-coding (telomeres, introns, promoters, enhancers) -Autosomal chromosome tend to be larger than sex chromosomes -variations in gene size/structure

Question 34

State the units for measuring genome size.

Answer 34

Databases present genome sizes using a measure known as a C-value -The C-value is the haploid nuclear DNA content of an organism -C-value units in mass: picograms (pg) -C-value units in number of bases: megabases (Mb)

Question 35

Define “sequence” in relation to genes and/or genomes. State that technological improvements have sped the DNA sequencing process. List applications of genome sequencing. Discuss ethical considerations of genome sequencing.

Question 36

Compare sexual and asexual reproduction. Discuss difficulties in applying the biological species concept to asexually reproducing species such as dandelions. Define horizontal gene transfer. Discuss difficulties in applying the biological species concept to bacteria that have horizontal gene transfer.

Question 37

Explain how sexual reproduction maintains chromosome number within a species. Outline the mating of a donkey and a horse to produce a sterile mule as an example of cross-breeding between closely related species producing sterile offspring because of differences in parent chromosome numbers.

Question 38

Explain the use of a dichotomous key in the identification of a specimen.

Question 39

Define “DNA barcode” and “environmental DNA.” Outline the use of “DNA barcoding” to identify species from environmental DNA. List applications of DNA barcoding using environmental DNA.

Answer 39

method of species identification using a short, standardized section of an organism's DNA (when morphology is difficult) -larvae