🧬 • Lesson 1.8 : Inheritance, Variation & Selection (Bio)

Question 1

What are chromosomes made of?

Answer 1

Chromosomes are made of DNA, which contains genetic information in the form of genes.

Question 2

What is a gene?

Answer 2

A gene is a length of DNA that codes for a protein.

Question 3

What is an allele?

Answer 3

An allele is an alternative form of a gene.

Question 4

How is sex inherited in humans?

Answer 4

Sex in humans is inherited through the XX and XY chromosomes.

Females have XX, and males have XY.

Question 5

What is a haploid nucleus?

Answer 5

A haploid nucleus contains a single set of chromosomes.

Question 6

What is a diploid nucleus?

Answer 6

A diploid nucleus contains two sets of chromosomes.

Question 7

What is the chromosome number in a human diploid cell?

Answer 7

In a diploid cell, there is a pair of each type of chromosome, and in a human diploid cell, there are 23 pairs.

Question 8

What is mitosis?

Answer 8

Mitosis is nuclear division that gives rise to genetically identical cells.

Question 9

What is the role of mitosis?

Answer 9

Mitosis plays a role in growth, repair of damaged tissues, replacement of cells, and asexual reproduction.

Question 10

What happens before mitosis?

Answer 10

The exact replication of chromosomes occurs before mitosis.

Question 11

What happens during mitosis?

Answer 11

During mitosis, the copies of chromosomes separate, maintaining the chromosome number in each daughter cell.

Question 12

What is meiosis involved in?

Answer 12

Meiosis is involved in the production of gametes.

Question 13

What is meiosis?

Answer 13

Meiosis is reduction division in which the chromosome number is halved from diploid to haploid, resulting in genetically different cells.

Question 14

What is inheritance?

Answer 14

Inheritance is the transmission of genetic information from generation to generation.

Question 15

What is genotype?

Answer 15

Genotype is the genetic make-up of an organism, defined by the alleles present.

Question 16

What is phenotype?

Answer 16

Phenotype refers to the observable features of an organism.

Question 17

What is homozygous?

Answer 17

Homozygous means having two identical alleles of a particular gene.

Question 18

What happens when two homozygous individuals breed?

Answer 18

Two identical homozygous individuals that breed together will be pure-breeding.

Question 19

What is heterozygous?

Answer 19

Heterozygous means having two different alleles of a particular gene.

Question 20

True or False ; A heterozygous individual will be pure-breeding.

Answer 20

False. A heterozygous individual will not be pure-breeding.

Question 21

What is a dominant allele?

Answer 21

A dominant allele is expressed if it is present in the genotype.

Question 22

What is a recessive allele?

Answer 22

A recessive allele is only expressed when there is no dominant allele of the gene present in the genotype.

Question 23

What are pedigree diagrams used for?

Answer 23

Pedigree diagrams are used to interpret the inheritance of a given characteristic.

Question 24

How do you predict the results of monohybrid crosses?

Answer 24

Use genetic diagrams to predict monohybrid cross results and calculate phenotypic ratios, limited to 1:1 and 3:1 ratios.

Question 25

How do you use Punnett squares in genetic crosses?

Answer 25

Use Punnett squares in crosses to work out and show the possible different genotypes.

Question 26

What is variation?

Answer 26

Variation is the differences between individuals of the same species.

Question 27

What is continuous variation?

Answer 27

Continuous variation results in a range of phenotypes between two extremes; (ex. body length).

Question 28

What is discontinuous variation?

Answer 28

Discontinuous variation results in a limited number of phenotypes with no intermediates; (ex. ABO blood groups).

Question 29

What is mutation?

Answer 29

Mutation is a genetic change.

Question 30

How are new alleles formed?

Answer 30

Mutation is the way in which new alleles are formed.

Question 31

What is genetic variation in natural selection?

Answer 31

Genetic variation within populations refers to the differences in genes and traits among individuals in a population.

Question 32

What does production of many offspring mean in natural selection?

Answer 32

Production of many offspring ensures that some will survive despite environmental challenges.

Question 33

What is the struggle for survival in natural selection?

Answer 33

The struggle for survival includes competition for resources such as food, space, and mates.

Question 34

How do better-adapted individuals pass on their alleles?

Answer 34

These individuals pass on their advantageous alleles to the next generation.

Question 35

What is an example of natural selection in bacteria?

Answer 35

The development of antibiotic-resistant bacteria is an example of natural selection, where bacteria with resistance survive and reproduce.

Question 36

What is selective breeding?

Answer 36

Selective breeding is the process where humans select individuals with desirable features to reproduce.

Question 37

How does crossing individuals in selective breeding work?

Answer 37

Humans cross individuals with desirable features to produce the next generation.

Question 38

How is selective breeding carried out over generations?

Answer 38

Selective breeding improves crop plants and domesticated animals over many generations by selecting for specific traits.