Inheritance

Question 1

What is genotype

Answer 1

The difference in genes

The genetic makeup of an organism

Question 2

What is a phenotype

Answer 2

The genotype represented as physical features

Question 3

What is an allele

Answer 3

An allele is a version of a gene that forms a specific characteristic

Question 4

What is genetic variation

Answer 4

the differences in DNA sequences among the same species

Question 5

What is environmental variation

Answer 5

Difference in phenotype between individuals of the same species that are caused by their surroundingsk, rather than their genes

Question 6

Examples of environmental variation

Answer 6

Accents
Broken bones
Scars

Question 7

Examples lf genetic variation

Answer 7

Eye choir
Hair type
Hair colour

Question 8

Examples of both genetic and environmental variation

Answer 8

Heights
Shoes size
Skin colour

Question 9

What is a chromosome

Answer 9

Tightly coiled DNA

Question 10

what is a gene

Answer 10

A section of DNA that codes for a specific protoen that controls the expression and developments of different characteristics

Question 11

What is reproduction.

Answer 11

The passing down of characteristics to an organisms offspring in order to ensure the species survival

Question 12

What happens in asexual reproduction.

Answer 12

Identical copies of the 1 parent will be made

Question 13

What happens in sexual reproduction

Answer 13

Chromosomes are passed from both parents meaning genetic variation occurs

Question 14

Advantages of asexual reproduction

Answer 14

-> less energy used
-> quicker, as only one parent is needed
-> if the parent is well adapted to the environment then the offspring also will be

Question 15

Disadvantages of asexual reproduction

Answer 15

-> there is no genetic variation amongst the species
-> if a diesease were to affect the organism, tje organisms would not be able to adapt and evolve to .

Question 16

How many chromosomes do normal human cells havw

Answer 16

46

Question 17

How many chromosomes do human gametes have

Answer 17

23

Question 18

Haploid and diploid meaning

Answer 18

-> haploid has 23 chromosomess
-> diploid has 46 chromosomes

Question 19

What is fertilisation

Answer 19

The two gamete’s join
The nuclei fuse
The cell formed is called a zygote

Question 20

What is a genome

Answer 20

All of the genetic material in an organism

Question 21

What is meiosis essentially

Answer 21

It’s mitosis repeated twice, but in the second repeat the chromosomes aren’t replicated

Question 22

Stages of meiosis

Answer 22

Stage 1
-> chromosomes replicated
-> line up along equator
-> pulled to opposite poles kf the cell
-> cell divides
-> cytokinesis

Stage 2
-> chromosomes again line up in centre of cell
-> get pulled apart
-> cell divides

Now, there are only 23 chromosomes as the chromosomes were not replicated in the second phase

Question 23

Why are mitosis and meiosis different

Answer 23

Mitosis has only one stage, and one cell division, and forms 2 genetically identical daughter cells and forms diploid cells

Meiosis has two stages, 2 cell divisions, amd forms 4 genetically different daughter cells from the parent cell. The cells formed are haploid meaning they only have half the number of chromosomes

Question 24

What are genes, alleles chromosomes and DNA

Answer 24

An allele is a specific version of a gene that codes for a particular characteristic. A gene is a section of DNA that carries the instructions for making a protein. DNA is coiled up to form chromosomes, which are found in the nucleus of a cell.

Question 25

What affect do mutations have on organisms

Answer 25

Mutations can give survival advantages or they can be negative, potentially harming protein function

Question 26

What is non coding DNA

Answer 26

Some regions of DNA that do not encode protein sequences, and control the expression of surrounding genes by switching them off or tuning them on (stopping transcription)

Question 27

What happens when there is a mutation in coding DNA

Answer 27

- This type of mutation causes changes in a protein produced by DNA transcription and translation. - This can affect the protein's structure and/or function.

Question 28

What happens when a mutation occurs in a section of non coding DNA

Answer 28

- A mutation in non-coding DNA doesn't affect the proteins produced by transcription and translation. - But it does affect the transcription process by either 'switching on' or 'switching off' certain genes, whjch means that it can either stop transcription from occurring or can make it happen - This causes an increase or decrease in the amount of a protein that is produced

Question 29

What does switching on or switching off genes

Answer 29

Switching on genes mean they are being expressed Switching off genes means they will not be expressed Caused by mutations in non coding dna

Question 30

Do mutations affect phenotype or genotype

Answer 30

Most mutations only affect genotype NOT PHENOTYPE

Question 31

What are the two types of variations

Answer 31

Continuous and discontinuous

Question 32

What is continuous variation

Answer 32

- There are no limits on the values that this type of variation can take.

Question 33

What affects continuous variation

Answer 33

is normally affected by a combination of genes and the environment.

Question 34

Examples of continuously variatjom

Answer 34

Height is an example of continuous variation

Question 35

What is discontinuous variation

Answer 35

Individuals fall into a number of distinct catego

Question 36

How is discontinuous variation determined

Answer 36

It is often determined only by genes

Question 37

Examples kf discontinuous variation

Answer 37

Blood type Eye colour

Question 38

Monohybrid inheritance meaning

Answer 38

refers to the inheritance of traits determined by a single gene. Punnet squares are used to visualise these outcomes

Question 39

What chromosomes do males and females havw

Answer 39

Make = XY Female = XX

Question 40

how to determine whether someone is male or female

Answer 40

If a sperm has X chromosome then it’s a girl If a sperm has Y chromosome it’s a boy

Question 41

Hwat chromosomes do egg cells all ways contain

Answer 41

X always never y Father determines gender

Question 42

What causes cystic fribrosis

Answer 42

A recessive allele

Question 43

What is a mutation

Answer 43

A change in the base sequence in DNA

Question 44

What are coding sections of DNA called

Answer 44

Genes

Question 45

What happens when a mutatiom occurs in a gene

Answer 45

DNA bases may be Changed Added Deleted

Question 46

What did Gregor Mendel find out

Answer 46

Observed characteristics were passed on from parent to offspring He realised the characteristics were determined by hereditary ‘units’ He found out all units were dominant or recessive

Question 47

What are start codons and what hallens kf a mutation occurs in them

Answer 47

Start codons are codons that are found on the mRNA that signal the ribosome to start translation If a mutation occurs in the start codon, it cannot cause translation to start, then the gene may not be translated, which means the protein will not be made.

Question 48

What is the difference between genotype and phenotype? How to write each?

Answer 48

Genotype: The genetic makeup of an organism (the alleles it has). Example: Bb Phenotype: The physical expression of the genotype (observable characteristics). Example: Blue eyes

Question 49

Function of genes

Answer 49

Determine production of proteins Controls the development and expression of different characteristics

Question 50

Do most mutations affect the orgnamjsm

Answer 50

No, most mutations have little to no effect on the protein the gene codes for