1.4 Flashcards
What is a phenotype?
Appearance of a trait, e.g., blue eyes
Phenotype refers to the observable characteristics that result from the interaction of an organism’s genotype with the environment.
What is a genotype?
The gene makeup of an organism for a specific trait
Genotype describes the genetic constitution of an organism, particularly concerning a specific characteristic.
Define asexual reproduction.
Reproduction involving one parent producing an exact copy of itself
Asexual reproduction does not involve the fusion of gametes and results in offspring that are genetically identical to the parent.
What does diploid mean?
Two sets of each chromosome
Diploid cells contain two complete sets of chromosomes, one from each parent.
What is sexual reproduction?
Reproduction requiring two parents that contribute genes to the offspring
Sexual reproduction results in offspring that have a combination of traits from both parents.
What does haploid refer to?
One set of each chromosome (Gametes)
Haploid cells contain only one set of chromosomes, which is typical for gametes like sperm and eggs.
What is mitosis?
Type of cell division producing two identical daughter cells
Mitosis is involved in growth and repair, resulting in cells with the same genetic makeup as the parent cell.
Define meiosis.
Reduction division that cuts the number of chromosomes in half
Meiosis produces gametes and occurs only in the reproductive system.
What is the result of meiosis?
Four daughter haploid cells with 23 chromosomes
Meiosis results in gametes that are genetically diverse due to processes like crossing over.
What is cross-over in genetics?
Exchange of genetic material between two sister chromosomes
Cross-over increases genetic variation in gametes during meiosis.
Define a population in biological terms.
A group of members of the same species living together in the same area
Members of a population can typically breed with each other.
What is the relationship between sexual reproduction and evolution?
Sexual reproduction leads to variation, which drives evolution
Without sexual reproduction, organisms would be genetically identical to their parents, limiting variation and evolution.
True or False: If mitosis were used instead of meiosis in sexual reproduction, there would be too many chromosomes in the new cells.
True
Using mitosis would result in an abnormal number of chromosomes, as it would not reduce the chromosome number appropriately.
Fill in the blank: Meiosis produces gametes with ______ of the DNA.
½
This reduction is crucial for maintaining the correct chromosome number in offspring.
What does meiosis result in that enhances genetic diversity?
Reshuffling of existing genes and production of different gametes
Meiosis allows for genetic variation through independent assortment and crossing over.
What role do mutations play in evolution?
Mutations change the genotype, which can affect the phenotype
Mutations introduce new genetic variations that can be advantageous for survival and reproduction.
