d3.2

This set of flashcards covers key concepts in genetics, including reproduction, inheritance patterns, genotype and phenotype definitions, and specific disorders.

What is the difference between sexual and asexual reproduction?

Asexual reproduction produces genetically identical clones, whereas sexual reproduction increases genetic variation by combining genes from two parents.

What type of cells undergo meiosis to produce gametes?

Diploid cells in gonads undergo meiosis to produce haploid gametes.

What is the result of fertilization?

Fertilization results in the formation of a diploid zygote that contains genetic information from both parents.

What are the male and female parts of a flower called?

The male part is the stamen, and the female part is the pistil.

What did Mendel find when he crossed true-breeding plants?

The F1 generation showed only one dominant trait, while the F2 generation showed a reappearance of recessive traits.

What is a genotype?

A genotype is the combination of alleles inherited by an organism.

Define homozygous and heterozygous.

Homozygous refers to having two identical alleles for a gene, whereas heterozygous refers to having two different alleles for a gene.

What is the phenotype?

The phenotype is the observable traits of an organism resulting from its genotype and environmental factors.

How do dominant and recessive alleles affect phenotype?

A dominant allele needs to be inherited from only one parent to be expressed, while a recessive allele must be inherited from both parents to be expressed.

What is phenotypic plasticity?

Phenotypic plasticity is the ability of an organism's phenotype to change due to environmental conditions.

What is phenylketonuria (PKU)?

PKU is a recessive disorder caused by mutations in chromosome 12 that affect the PAH gene, leading to toxic buildup of phenylalanine if untreated.

What are single-nucleotide polymorphisms (SNPs)?

SNPs are mutations where a single nucleotide in DNA is changed and can influence genetic variation within a population.

What determines blood type in humans?

Blood type is determined by multiple alleles (A, B, O) on chromosome 9, which affect the antigens present on red blood cells.

What does codominance mean?

Codominance occurs when both alleles are expressed equally in the phenotype of heterozygotes.

How is sex determined in humans?

Sex is determined by the 23rd pair of chromosomes, where the egg always carries an X chromosome and the sperm carries either an X or a Y.

What is haemophilia?

Haemophilia is a sex-linked genetic disorder that affects blood clotting and is caused by mutations on the X chromosome.

What are pedigree charts used for?

Pedigree charts are used to show inheritance patterns of traits through family history and predict disease inheritance in future generations.

What is polygenic inheritance?

Polygenic inheritance is a form of inheritance where multiple genes influence a single trait, such as skin color.

What effect does crossing over have on linked genes?

Crossing over increases genetic variation and can result in recombinant genes if genes are far apart on a chromosome.

What is the purpose of a chi-squared test in genetics?

The chi-squared test compares observed versus expected offspring ratios to determine if differences are statistically significant or due to chance.