genetics

Question 1

Law of independent assortment

Answer 1

alleles are assorted into gametes independently separating from each other without influencing each other (alleles do not go into each other’s gametes)

Question 2

Law of segregation

Answer 2

only one allele is carried in a gamete, one allele of a gene is given to each gamete they produce.

Question 3

Homozygous

Answer 3

same alleles for a particular trait (ex. RR

Question 4

Heterozygous

Answer 4

expressing two different alleles for a particular trait (ex. Rr)

Question 5

Homologous chromosome

Answer 5

a pair of chromosomes They carry the same genes and is diploid.

Question 6

Gamete

Answer 6

a mature haploid reproductive cell

Question 7

Haploid

Answer 7

contains half the number of chromosome (single set of chromosomes

Question 8

Diploid

Answer 8

twice the number of chromosomes in a haploid cell

Question 9

Zygote

Answer 9

fertilized egg from the joining of sperm and an egg

Question 10

Nondisjunction

Answer 10

failure of one or more pairs of homologous chromosomes or sister chromatids to separate normally during meiosis

(the daughter cell have an unequal number of chromosomes) (ex. Down syndrome is one of the outcomes of this)

Question 11

Mutation

Answer 11

permanent change in the DNA sequence of a particular gene

Question 12

Inversion

Answer 12

part of the chromosome is broken off and reattached in a flipped state.

Question 13

Mutation

Answer 13

permanent change in the DNA sequence of a particular gene

Question 14

Sexual reproduction

Answer 14

involves the formation of haploid gametes through meiosis that fuse to form a diploid zygote. Slow reproduction with small numbers and high genetic variation.

Question 15

Asexual reproduction

Answer 15

involves one parent copying themselves, thus forming identical offspring. Parent generates offspring identical to itself and can reproduce in large numbers quickly with low genetic variation.

Question 16

Meiosis

Answer 16

process that halves the amount of DNA to create sperm or egg cells.

Results in 4 genetically unique daughter cells because DNA is taken from each parent.

They are all genetically unique because they can cross over and also line up differently.

Chromosomes line up next to each other to get pulled apart.

Question 17

Mitosis

Answer 17

process that splits replicated cells into two identical daughter cells.

Both sexual and asexual reproducing organisms go through mitosis.

Chromosomes line up on top of each other in single file in the centre.

Question 18

Function (type of cell) for mitosis

Answer 18

Growth and repair (somatic cell)

Question 19

Function (type of cell) for meiosis

Answer 19

Reproduction – sperm and egg (sex cell)

Question 20

What causes genetic variation for mitosis

Answer 20

Mutations

Question 21

What causes genetic variation for meiosis

Answer 21

Different DNA coming from the two parents

Question 22

Complete Dominance

Answer 22

• Dominant trait is visible and recessive trait will be hidden by dominant allele
• Coding: RR, Rr, rr
• 2 phenotypes

Question 23

Incomplete Dominance

Answer 23

• Neither allele is truly dominant
• Blending of traits (ex. Red + white = pink)
• Coding: RR, RR’, R’R’
• 3 phenotypes

Question 24

Codominance

Answer 24

• Both alleles for a trait are dominant
• Cattle example (red + white = roan)
• Chicken example (black + white = checkered)
• 3 phenotypes
• Coding: RR, RW, WW

Question 25

Multiple Alleles

Answer 25

- Genes that can have more than 2 alleles - Blood type example (type A, B, O)

Question 26

Sex Linkage

Answer 26

- Inheritance of X and Y chromosomes - X carries DNA but Y does not