Genetics SAC 1B Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

Diploid

A

Cells with two sets of chromosomes (2n), one set derived from each parent. In humans the diploid number is 46

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

haploid

A

Cells with one set of chromosomes (n). These cells are produced by meiosis. In humans the haploid number is 23

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Gene

A

A section of DNA that codes for a protein, basic unit of heredity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Allele

A

Alternative form of a gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Genotype

A

genetic makeup of an individual, wither in relation to a trait, or a set of traits. e.g. FF, Ff, ff

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Phenotype

A

The physical, biochemical, physiological expression of the genotype. It is influenced by the environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

recessive

A

2 identical alleles must be present to observe the trait

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

autosomal

A

gene is located on an autosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

sex-linked

A

gene is located on the sex chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

heterozygous

A

2 different alleles. e.g, Ff

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

homozygous

A

2 identical alleles. e.g. FF or ff

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

complete dominance (dominant trait)

A

one allele completely masks the effect on another allele. Dominant traits are observed if only one copy of the affected allele is present.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

co dominance

A

both alleles are expressed in a heterozygous therefore a third phenotype is observed.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

multiple alleles

A

where there are more than two alleles for a particular gene in the population, but only 2 can ever be present in an individual. E.g. blood groups

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

continuous variation

A

many intermediate forms of the trait, which follow a normal distribution. E.g. height in humans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

discontinuous variation

A

descrete, non-overlapping classes of phenotypes.

17
Q

monogenic inheritance

A

trait determined by one gene with two or more alleles.

18
Q

polygenic inheritance

A

trait determined by many genes.

19
Q

Pedigree

A

graphic representation using standard symbols showing the pattern of occurrence of an inherited trait in a family.

20
Q

Monohybrid crosses

A

a cross in which alleles of only one gene are involved.

21
Q

Test cross

A

a mating (set up by humans) where an individual with the dominant phenotype is crossed/ mated with an individual with the recessive trait.

22
Q

Why are test crosses used?

A

they can determine whether the parent with the dominant trait is homozygous or heterozygous, by observing the ratio of dominant to recessive traits in the offspring.