The key event in the transition of the amphibians from water to land is the ________
replacement of the gills with lungs
possession of webbed limbs
limbs
possession of tympanic membrane
Correct answer is A
Amphibians display some interesting and changing characteristics as they metamorphose through various forms on their way to adulthood. The frog, for instance, begins life underwater as a larva with gills and becomes and air-breather with lungs as an adult.
&therefore4; in case of draught, frog can amphibians can use lungs to breathe on land.
Which of the following is an example of active transport?
Oxygen exchanging between red blood cells and liver cells
Carbon dioxide exchanging between muscle cells and red blood cells
Water moving out of the small intestine
Sodium being reabsorbed in the kidney
Correct answer is D
Although sodium ions are small, their charge prevents them from moving across the cell membrane through simple diffusion. They must be transported using active transport.
The lungs of the lung fish is an adaptation for respiration _______?
to complement gills while in water
to complement gills while on land
while on land
while in water
Correct answer is B
Lungfish are best known for retaining the ability to breathe air, to survive drought.
birds and reptiles
fishes and birds
reptiles and fishes
birds and molluscs
Correct answer is A
Its long been recognized that birds and reptiles share many characteristics:
Both have skulls that abut the first neck vertebra with a single ball-and-socket joint.
Both birds and reptiles excrete nitrogenous wastes as uric acid; mammals excrete urea, fish ammonia.
Both lay similar highly yolked eggs
Bird feather is homologous to the reptile scale. Both develop from an epidermal elevation over a nourishing dermal core. Scales flatten, feather buds roll into a cylinder shaped tube.
The product after the union of the male and female gamete in animals is called
sperm
egg
embryo
zygote
Correct answer is D
Human fertilization is the union of a human egg and sperm, usually occurring in the ampulla of the fallopian tube.
The result of this union is the production of a zygote cell, or fertilized egg, initiating prenatal development.