Honors Biology Finals Review

Describe the process of mitosis

It’s a nuclear division where a cell goes through Prophase, Metaphase, Anaphase, and Telophase (PMAT) and it goes through Mitosis in order to duplicate with the same number of chromosomes as the original.

Describe the process of meiosis

The number of chromosomes in the original cell is reduced by HALF through the separation of homologous chromosomes.

Similarities that mitosis and meiosis share

They both go through duplication of cells and they need the exact same chromosomes in their daughter cells.

In animals, when does meiosis occur?

During gamete formation

What is crossing over?

When homologous chromosomes are aligned then they “cross over” the bottom portion and exchange each other in order to have genetic variation

What is the outcome of crossing over when it comes to the process of meiosis?

Genetic variation

What is a karyotype?

It is an individual’s complete set of diploid chromosomes and humans have 23

How can a karyotype be used to identify a male or female?

XY is a male and XX is a female

How can a karyotype be used to identify a chromosomal abnormality? 

Through the number or arrangement of the chromosomes

Chromosomes that are the same size, shape and contain genes that code for the same kind of information are defined as?

Homologous pairs

Which combination of sex chromosomes represent female?

XX

Which combination of sex chromosomes represent male?

XY

Which chromosomes are called autosomes?

One of the numbered chromosomes, NOT a sex chromosome

Which chromosomes are called sex chromosomes?

The ones that determine the gender

What are haploid cells?

A cell that contains a single set of chromosomes

What are diploid cells?

A cell that contains 2 copies of each chromosome

How does a chromosomal abnormality like trisomy 21 (Down Syndrome) occur during meiosis?

Error during the formation of the egg or sperm

What holds together the nitrogen bases in the DNA?

Hydrogen bond

RNA is found in what part of the cell?

The nucleus and the cytoplasm

What components make up a nucleotide?

Nitrogenous base (AGCT/U), a phosphate group, and a sugar molecule (deoxyribose in DNA and ribose in RNA)

What are the differences between DNA and RNA?

DNA is double stranded and the sugar is deoxyribose, and RNA is single stranded and sugar is ribose. RNA is also allowed to leave the nucleus and instead of using Thymine, it uses Uracil, which is very similar to Thymine

What is a gene?

Genetic information stored in a chromosome

What information is found on the gene?

Genetic

What are the three types of RNA?

tRNA (transfer RNA), mRNA (messenger RNA), rRNA (ribosomal RNA)

What is the function of tRNA?

Carries amino acids to the ribosomes during protein synthesis

Which process has the instructions for making proteins (“recipes”)?

translation

The code of mRNA is directly dependent upon what?

The nitrogen base pairs in DNA

What contains the anticodon and transports the amino acid?

tRNA

What enzyme is used in the process of transcription.

RNA polymerase

What is the step of protein synthesis takes place at the ribosome?

Translation

What is produced during transcription?

A single stranded RNA molecule that is complementary to one strand of DNA

Where does the process of transcription take place?

The nucleus

Where does protein synthesis take place?

Ribosomes

How many codons are needed to specify 7 amino acids?

147, 21 codon per amino acid

What are intron and exons?

Introns are the noncoding sections of an RNA transcript and they are spliced out before the RNA molecule is translated and the sections of RNA that codes for proteins are exons.

When do intron and exons appear in the protein synthesis? (what stage)

Right after transcription

What is a Punnett square used for?

To predict the variations and probabilities that can come from cross breeding

What is a homozygous individual?

An individual who has inherited the same versions (alleles) of a genomic marker from each biological parent

What is a heterozygous individual?

An individual who has different alleles for a particular trait

The genetic makeup of an organism for a hereditary characteristic is referred to as what?

Genotype

What is complete dominance?

One trait over the other

What is codominance?

Both traits having equal dominance, such as a pattern of red and white on a flower

What is incomplete dominance?

None of the traits have dominance, they “mix”, such as a pink flower from a red and white flower

What is a polygenic trait?

A phenotype which is influenced by more than one gene

What is evolution

A theory that is supported by a substantial evidence, all the changes that have formed life on earth from its beginnings to the diversity we see today, and the gradual change in species over time

What is fitness

A measure of an organism’s ability to reproduce

What is variation

Difference within a trait of a species

What is mutation

A change in DNA sequence

What is adaptation

It is an inherited trait that increases an organism’s chance of survival

What is species

A group of individuals that can reproduce with one another and have fertile offspring

What is a population

A group of organisms of the same species living in the same geographic area at the same time

What is a gene pool

All of the genes (alleles) for a trait in a given population at any one time

How does an organism get an adaptation?

Through a mutation

What is the name of the process that carries out evolution?

Natural selection

What is competition

A relationship between organisms that strive for the same resources in the same place.

Can an individual organism evolve in its own lifetime?

No

Can a species evolve generation to generation?

No

In which rock type do we find fossils?

Sedimentary

What is the Law of Superposition?

States that the bottom layer of a rock formation is older than the layer on top.

How does reproductive isolation lead to speciation?

Over generations differences build up between the populations.

What is an index fossil?

Fossils of widely distributed organisms that lived during only one short time period

What is tectonic plates?

Large slabs of rocks that divide Earth’s crust

How do plates move?

Convection currents driven by heat in Earth’s mantle move plates in different directions

Two organisms can be considered to be part of the same species when what event happens?

They can reproduce and have fertile offspring

How are fossil fuels formed

When prehistoric plants and animals died and were gradually buried by layers of rock

What are the 3 main fossil fuels?

Coal, oil, and gas

What are the 3 main greenhouse gases?

Carbon dioxide, methane, and nitrous oxide

What is the greenhouse effect?

A process that occurs when gases in Earth’s atmosphere trap the Sun’s heat

How does the greenhouse effect affect the Earth’s atmosphere?

Traps radiation from the sun

What is a natural resource?

Materials found in the enviornment

Give three examples of a natural resource

Water, soil, and forests

What is a nonrenewable resource

Limited in supply resources

Give 3 examples of a nonrenewable resource

Oil, coal, and nuclear energy

Which type of cells are haploid?

Gametes

Which type of cells are diploid?

Somatic