Biology — Semester A Practice

Question 1 of 10

TEKS 7A-7F Easy Diagram

Which of these represents an adaptation that improves survival?

A Only the cactus spines

B Only the polar bear fur

C All three are adaptations that improve survival

D None of them

Explanation

All three are adaptations: cactus spines reduce water loss in deserts; white fur camouflages polar bears in snow; long necks let giraffes reach food competitors can't.

Question 2 of 10

TEKS 1A-3F Easy Word Diagram

Which graph correctly shows exponential growth?

A Neither

B B

C Both

D A

Explanation

📌 Exponential growth = J-shaped curve (slow start, rapid increase)
Linear growth = straight line (constant rate)
Graph A shows exponential growth.

Question 3 of 10

TEKS 7A-7F Medium Word Diagram

The graph shows the change in a moth population over time. Dark moths increased after industrial pollution darkened tree bark. This is an example of:

A Spontaneous generation

B Genetic engineering

C Natural selection

D Artificial selection

Explanation

📌 This is the classic peppered moth example of natural selection.
Before pollution: light bark → light moths camouflaged → survived
After pollution: dark bark → dark moths camouflaged → survived
The environment selected for the trait that provided camouflage.

Question 4 of 10

TEKS 8A-8C Easy Image

The image shows the taxonomic hierarchy. Which level contains organisms most similar to each other?

A Domain

B Kingdom

C Class

D Species

Explanation

Species is the most specific (narrowest) level — organisms in the same species can interbreed and produce fertile offspring.

Question 5 of 10

TEKS 4A-5D Easy Word Image

Which organelle is labeled X in the cell diagram below?

A Nucleus

B Golgi apparatus

C Endoplasmic reticulum

D Mitochondria

Explanation

📌 Organelle X has the bean-shaped structure with inner folds (cristae) → Mitochondria
Mitochondria = powerhouse of the cell = produces ATP through cellular respiration
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ATP

Question 6 of 10

TEKS 1A-3F Medium Word Image

A student designed an experiment to test how light affects plant growth. Identify the components of this experiment.

A Independent: temperature; Dependent: light

B Independent: light; Dependent: plant height

C Independent: plant height; Dependent: light

D Independent: water; Dependent: soil

Explanation

📌 Independent variable = what you change (light)
Dependent variable = what you measure (plant height)
Control group = no light (to compare against)
Constants = same soil, water, temperature, pot size

Question 7 of 10

TEKS 4A-5D Easy Word Diagram

The diagram shows the structure of a DNA nucleotide. What are the three components?

A Lipid, protein, carbohydrate

B Phosphate, sugar, nitrogenous base

C Amino acid, sugar, phosphate

D Glucose, ATP, enzyme

Explanation

📌 Each DNA nucleotide has 3 parts:
1. Phosphate group (connects nucleotides)
2. Deoxyribose sugar (5-carbon sugar backbone)
3. Nitrogenous base (A, T, G, or C — carries genetic info)

The bases pair: A-T and G-C

Question 8 of 10

TEKS 8A-8C Easy Image

The diagram shows the three domains of life. Which domain contains organisms with no membrane-bound nucleus and lives in extreme environments?

A Plantae

B Eukarya

C Archaea

D Bacteria

Explanation

Archaea are prokaryotes (no nucleus) and many live in extreme environments (hot springs, salt lakes, deep-sea vents). Bacteria are also prokaryotes but typically not extremophiles.

Question 9 of 10

TEKS 1A-3F Easy Image

The image shows lab equipment. Which is used to measure precise volumes of liquid?

A Graduated cylinder

B Beaker

C Test tube

D Erlenmeyer flask

Explanation

A graduated cylinder is designed for accurate volume measurement (markings are precise). Beakers and flasks are for rough volumes only.

Question 10 of 10

TEKS 8A-8C Easy Word Diagram

The diagram shows the three domains of life. Which domain contains organisms that live in extreme environments?

A Bacteria

B Archaea

C All three equally

D Eukarya

Explanation

📌 Archaea = prokaryotes that often live in EXTREME environments:
• Hot springs (thermophiles)
• Salt lakes (halophiles)
• Deep ocean vents
• Acidic environments

Bacteria = prokaryotes in common environments
Eukarya = all eukaryotes (plants, animals, fungi, protists)

Explanation

Explanation

Explanation

Explanation

Explanation

Explanation

Explanation

Explanation

Explanation

Explanation

Want unlimited practice?