🧬 • Lesson 1.8 : Inheritance, Variation & Selection (Bio) Flashcards
This deck goes into depths about chromosomes and genes, DNA, cell division, inheritance, alleles, variation in species, and natural selection.
What are chromosomes made of?
Chromosomes are made of DNA, which contains genetic information in the form of genes.
What is a gene?
A gene is a length of DNA that codes for a protein.
What is an allele?
An allele is an alternative form of a gene.
How is sex inherited in humans?
Sex in humans is inherited through the XX and XY chromosomes.
Females have XX, and males have XY.
What is a haploid nucleus?
A haploid nucleus contains a single set of chromosomes.
What is a diploid nucleus?
A diploid nucleus contains two sets of chromosomes.
What is the chromosome number in a human diploid cell?
In a diploid cell, there is a pair of each type of chromosome, and in a human diploid cell, there are 23 pairs.
What is mitosis?
Mitosis is nuclear division that gives rise to genetically identical cells.
What is the role of mitosis?
Mitosis plays a role in growth, repair of damaged tissues, replacement of cells, and asexual reproduction.
What happens before mitosis?
The exact replication of chromosomes occurs before mitosis.
What happens during mitosis?
During mitosis, the copies of chromosomes separate, maintaining the chromosome number in each daughter cell.
What is meiosis involved in?
Meiosis is involved in the production of gametes.
What is meiosis?
Meiosis is reduction division in which the chromosome number is halved from diploid to haploid, resulting in genetically different cells.
What is inheritance?
Inheritance is the transmission of genetic information from generation to generation.
What is genotype?
Genotype is the genetic make-up of an organism, defined by the alleles present.
What is phenotype?
Phenotype refers to the observable features of an organism.
What is homozygous?
Homozygous means having two identical alleles of a particular gene.
What happens when two homozygous individuals breed?
Two identical homozygous individuals that breed together will be pure-breeding.
What is heterozygous?
Heterozygous means having two different alleles of a particular gene.
True or False ; A heterozygous individual will be pure-breeding.
False. A heterozygous individual will not be pure-breeding.
What is a dominant allele?
A dominant allele is expressed if it is present in the genotype.
What is a recessive allele?
A recessive allele is only expressed when there is no dominant allele of the gene present in the genotype.
What are pedigree diagrams used for?
Pedigree diagrams are used to interpret the inheritance of a given characteristic.
How do you predict the results of monohybrid crosses?
Use genetic diagrams to predict monohybrid cross results and calculate phenotypic ratios, limited to 1:1 and 3:1 ratios.
How do you use Punnett squares in genetic crosses?
Use Punnett squares in crosses to work out and show the possible different genotypes.
What is variation?
Variation is the differences between individuals of the same species.
What is continuous variation?
Continuous variation results in a range of phenotypes between two extremes; (ex. body length).
What is discontinuous variation?
Discontinuous variation results in a limited number of phenotypes with no intermediates; (ex. ABO blood groups).
What is mutation?
Mutation is a genetic change.
How are new alleles formed?
Mutation is the way in which new alleles are formed.
What is genetic variation in natural selection?
Genetic variation within populations refers to the differences in genes and traits among individuals in a population.
What does production of many offspring mean in natural selection?
Production of many offspring ensures that some will survive despite environmental challenges.
What is the struggle for survival in natural selection?
The struggle for survival includes competition for resources such as food, space, and mates.
How do better-adapted individuals pass on their alleles?
These individuals pass on their advantageous alleles to the next generation.
What is an example of natural selection in bacteria?
The development of antibiotic-resistant bacteria is an example of natural selection, where bacteria with resistance survive and reproduce.
What is selective breeding?
Selective breeding is the process where humans select individuals with desirable features to reproduce.
How does crossing individuals in selective breeding work?
Humans cross individuals with desirable features to produce the next generation.
How is selective breeding carried out over generations?
Selective breeding improves crop plants and domesticated animals over many generations by selecting for specific traits.
