Test 3 study guide

Heterotrophs

Organisms that obtain their energy by consuming other organisms.

Autotrophs

Organisms that can produce their own food using light, water, carbon dioxide, or other chemicals.

Photosynthesis Equation

6CO2 + 6H2O + light energy → C6H12O6 + 6O2.

Chlorophyll a

The primary pigment in plants responsible for absorbing light for photosynthesis, reflecting green light.

Stomata

Small openings on the leaf surface that allow for gas exchange.

Chloroplasts

Organelles in plant cells where photosynthesis occurs.

Granum (Grana)

Stacks of thylakoids within chloroplasts where light-dependent reactions take place.

Thylakoids

Membrane-bound compartments inside chloroplasts involved in photosynthesis.

Function of sunlight in photosynthesis

Sunlight provides the energy needed to convert carbon dioxide and water into glucose.

Splitting of water in photosynthesis

Generates oxygen and provides electrons for the electron transport chain.

Calvin Cycle

Location of carbon fixation, using ATP and NADPH produced in the light-dependent reactions.

Genome

The complete set of genes or genetic material present in a cell or organism.

Diploid cells

Cells that contain two complete sets of chromosomes (2n), one from each parent.

Haploid cells

Cells that contain one complete set of chromosomes (n), typically gametes.

Homologous chromosomes

Pairs of chromosomes that are similar in shape, size, and genetic content.

Sister chromatids

Identical copies of a chromosome connected by a centromere.

Mitosis

The process of cell division that results in two identical daughter cells.

Gene mutations

Changes in the DNA sequence that can affect how genes function.

Proto-oncogene

A gene that promotes progression through the cell cycle.

Binary fission

A form of asexual reproduction where a single organism divides into two identical organisms.

Meiosis

A specialized form of cell division that reduces the chromosome number by half, creating haploid gametes.

Crossing over

The exchange of genetic material between non-sister chromatids during prophase I of meiosis.

Independent assortment

The random distribution of maternal and paternal chromosomes into gametes during meiosis, contributing to genetic diversity.

Human haploid chromosome number

23 chromosomes, consisting of 22 autosomes and 1 sex chromosome.

Karyotypes

A display of an individual's complete set of chromosomes, used to assess chromosomal abnormalities.

Aneuploidies

Abnormalities in chromosome number, typically resulting from nondisjunction during meiosis.

Polyploidies

Conditions where cells have more than two complete sets of chromosomes, often seen in plants.