B13.5 - 13.10 - Reproduction + DNA (set B)✔️

Question 1

Define gamete?

Answer 1

A gamete is a reproductive cell of an animal or plant

Question 2

define chromosome?

Answer 2

Really long structures of DNA found in the nucleus of animial and plant cells, carries genetic information in the form of genes - normally comes in pairs - 23 pairs of chromosomes in every human body cell

Question 3

Define gene?

Answer 3

Small section of DNA found on a chromosome - each gene codes for a particular sequence of amino acids which are put together to make a specific protein

Question 4

Define the term dominant allele?

Answer 4

dominant allele will always be expressed even if only 1 is present - and is represented with a capital letter eg Aa

Question 5

Define the term ressesive allele?

Answer 5

Both alleles must be ressesive for it to display ressesive characteristics - represented with lower case letter eg aa

Question 6

Define the term homozygous?

Answer 6

When two alleles for a particular gene are the same

Question 7

Define the term hetrozygous?

Answer 7

If two alleles for a particular gene are different

Question 8

Define the term genotype?

Answer 8

Describes the alleles present or genetic makeup of an idividual regarding characteristics for example Bb or bb

Question 9

Define the term phenotype?

Answer 9

Describes the physical apperance of an individual regarding a particular characteristic for example black fur or brown fur in a mouse

Question 10

How do characteristics controlled by genes differ?

Answer 10

Some characteristics are controlled by a single gene such as fur colour in mice and red-green colour blindness in humans - most characteristics are controlled by several genes interacting

Question 11

2 example of inherited disorders and what they are caused by?

Answer 11

• polydactyly (extra fingers or toes) caused by a dominant allele - inherited from either of both parents
• cystic fibrosis (disorder of cell membrane) caused by a recessive allele - inherited by both parents

Question 12

What are the letters for female sex chromosomes?

Answer 12

XX

Question 13

What are the letters of male sex chromosomes?

Answer 13

XY